<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>原生事件绑定</title>
</head>
<body>
    <button id="btn1">按钮1</button>
    <button id="btn2">按钮2</button>
    <button onclick="demo()">按钮3</button>

    <script>
        const btn1 = document.getElementById("btn1");
        btn1.addEventListener('click', function (){
            alert("按钮1被点击了");
        })

        const btn2 = document.getElementById("btn2");
        btn2.onclick = () => {
            alert("按钮2被点击了");
        }

        function demo() {
            alert("按钮3被点击了")
        }


    </script>


</body>
</html>